Method and apparatus for generating a number audio element in an audio system

ABSTRACT

A method and apparatus for generating a number audio element for playing a desired number in an audio system. Specifically, the method sets forth the steps of storing a plurality of audio elements used to represent a subset of the range of numbers; defining a plurality of match types used to determine if one or more matching audio element exists in the subset of the range of numbers; defining a plurality of accuracy prefixes representative of the error associated with any rounding of the desired number to be played; setting the accuracy prefix to a value representing an exact match between the desired number and a number audio element in the stored subset of audio elements representative of the range of numbers; filtering the audio elements to determine if an exact match exists; if an exact match does not exist, rounding the desired number to a pre-determined level of precision to create an estimated desired number; setting the accuracy prefix to a value representing the error associated with any rounding of the desired number to be played; filtering the audio elements to determine if an exact match exists between the estimated desired number and any of the plurality of audio elements used to represent a subset of the range of numbers; and repeating the steps of filtering until such time as an exact match has been determined between the estimated desired number and any of the plurality of audio elements used to represent a subset of the range of numbers. Once an exact match is determined, the number audio element is transmitted to a remote user. The number audio element may be a stock quote or an announcement of the time. Further, the number audio element may be transmitted in telephone systems, automated teller machines, or other audio systems.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method and system for providing anunlimited number of users an independently customized broadcast. Moreparticularly, the present invention relates to a method and system forproviding a customized radio station with the same variety and controlprovided today in traditional radio, but customized for each individualend user independently and simultaneously. The radio station generatedfor each user consists of audio elements that are customized for theindividual end user.

2. Background Discussion

Radio broadcasting provides a means for transmission of information andentertainment to millions of radio listeners. Traditional radiobroadcasting has required a full radio broadcast station to create andassemble a single set of content (music, advertising, etc.) that isbroadcast to all listeners. Current radio broadcasting attempts totailor its content to the particular audience that the station desiresto attract as listeners. For example, some radio stations dedicateprogramming to talk shows or a particular type of music (contemporary,country, etc.). However, current radio broadcast systems do not tailorcontent based on particular characteristics and desires of eachindividual listener.

The emergence of the Internet has provided an alternate transmissionmedia for traditional radio and other types of broadcasts. To use theInternet, broadcast signals must be digitized, packetized, andtransmitted to a remote user. Because these broadcasts are digitized,the broadcast signal may be stored for later transmission. An example ofa system that provides for later transmission of a broadcast signal isthe Internet jukeboxes available from companies such as RealNetworks.The RealNetworks system provides access to a collection of Internetmusic selected to fit the individual end user. Using the RealNetworkssystem, a user may select and receive music or other audio content upondemand. Other systems, such as LaunchCast from Launch.com, attempt toconstruct a collection of Internet music appropriate for the end user bymaking inferences from user feedback. In these systems, content isprovided using “streaming audio.” In other systems, video content isprovided using “streaming video.” That is, the audio and video contentis embedded for streaming playback within a web page. In addition, thesesystems stream audio or video to the user by selecting content from theuser's collection either randomly or on demand.

Although known Internet radio broadcast systems have provided someconvenience and advantage over traditional radio broadcasts, a number ofdisadvantages remain. For example, these Internet radio broadcastsystems lack the ability to create a customized audio program consistingof carefully controlled variety based upon a user's preferences,demographics, and listening history. Although some web-basedcustomizable newspapers have been developed that provide customized newsbased on a user's preferences and demographics, no system provides apersonal radio system that allows the user to customize the radiobroadcast content based on the user's preferences and demographics.

Therefore, a need exists for a personal radio system that iscustomizable based on the user's preferences and demographics. Morespecifically, a need exists for a radio broadcast system that allows auser to select the format and content to be provided within the radiobroadcast. In addition, a need exists for a personal radio system thatprovides a customizable radio experience over the Internet, but stillprovides the same experience to a listener as if listening to atraditional radio broadcast.

Further, a need exists for other types of server systems that provideother types of customizable content, including video content.

SUMMARY OF THE INVENTION

The present invention delivers a custom broadcast, assembled on demand,for each individual user. More particularly, the present inventiondelivers a custom radio station, assembled on demand, for each listener.Like traditional broadcast radio, the audio experience consists of musicintroduced by a disk jockey (DJ), jingles, news, sports, weather, stockreports, and advertisements. However, the present invention provides forthe transmission of a radio broadcast to an individual listener suchthat each of these audio elements is customized for the individual enduser. More particularly, by maintaining a user profile that representsthe preferences and particular interests of a user, and a user statethat maintains the recent listening history of the user, the presentsystem generates a uniquely tailored content stream that the user ismore likely to enjoy over traditional broadcast radio. The individual'slistening experience is continually refined and improved by modifyingthe user profile and updating the user state. The present inventionmodifies the user profile by using information gathered directly fromthe user, through collaborative filtering of other users, viadata-sharing partnerships, and through direct manipulation by radioprogrammers.

In an embodiment, the present invention includes a personal broadcastserver system for providing a customized broadcast to one or more usersover a transmission media. The personal broadcast server systemincludes: a data storage device for storing a plurality of broadcastelements; a data management system for storing a user profile and a userstate for each of the one or more users, wherein the data managementsystem further stores information associated with each of the pluralityof broadcast elements; a broadcast element selector having one or morebroadcast element selection functions, wherein each broadcast elementselection function is operable to select broadcast elements from thedata storage device based on a user's user profile, the user's userstate, and the information associated with each of the plurality ofbroadcast elements; and a broadcast server operable to receive theselected broadcast elements from the data storage device and to providethe selected broadcast elements to the user over the transmission media.

In alternate embodiments, the data storage device of the personalbroadcast server system is a file server or a database. In addition, thepersonal broadcast server system may be implemented as a singlecomputing device, or alternatively, mulitple computing devices.

The personal broadcast server system may also include a history of usagefor each of the users. Based on the history of usage, the presentinvention may prevent broadcast elements from being delivered to a user.

According to the present invention, the personal broadcast server systemmay be used to provide audio or video elements to a user. In anembodiment, the audio or video elements are streamed over the Internetto the user. The types of audio elements that may be provided to theremote use includes music, advertising, talk by a DJ, or other audiocontent.

In yet another embodiment of the present invention, the user profilesthat are stored in the data management system include initialregistration information derived from when the user first logs in.Alternatively, the user profiles include demographic informationrelating to each user. The user profiles may also include informationrelated to a user's preferred frequency of content, which may beautomatically updated based on the listening patterns of the user.

More specifically, the present invention provides a customized radiobroadcast to one or more users by providing a personal radio serversystem that includes a general purpose computer having a centralprocessing unit and memory for storing user profiles for one or moreusers. The central processing unit includes a program that causes thecentral processing unit to produce individual audio streams for each ofthe one or more users based on the user profiles stored in memory. Theindividual audio streams may be comprised of one or more audio elements,which may be stored on a filed server.

In another aspect of the present invention, a method of using a personalradio server for transmitting customized radio content to a remotelistener over a transmission media is provided. Specifically, the methodcomprises: storing a plurality of audio elements; dynamically generatingand updating a user profile that represents the preferences,demographics, and interests of the remote listener; selecting audioelements to provide to the remote listener based on the remotelistener's preferences, demographics, and interests; and transmittingthe audio elements to the remote listener over the transmission media.In alternate embodiments, the method further includes the steps ofmaintaining a history of the audio elements provided to the remote user,and selecting audio elements to provide to a user based on the historyof audio elements previously provided to the remote user.

In yet another embodiment, the method of providing customized radiocontent of provides for selecting audio elements by receiving andstoring a user's ratings of one or more audio elements; comparing theuser's ratings for the one or more audio elements to ratings from otherusers; predicting the user's ratings for different audio elements basedon ratings from other users with similar ratings to the user's ratingsof one or more audio elements; and selecting audio elements based on theuser's predicted ratings.

In an alternate embodiment, the method for providing a customized radiobroadcast to one or more users over a transmission media includes thesteps of generating a user profile for each user; selecting audioelements for each user based on each user's user profile; forming anindividual audio stream for each user from the audio elements; andtransmitting the individual audio streams to the one or more users overthe transmission media. Alternatively, audio elements may be selectedbased on the history of audio elements previously provided to the remoteuser. In yet another embodiment of the invention, audio elements may beselected based on a prediction of the user's ratings for different audioelements based on ratings from other users with similar ratings torelated audio elements. In still another embodiment, the audio elementsmay be selected by the user on-demand.

The customized radio broadcast server of the present invention may alsowork with a processor-based communications device operable to receiveaudio elements over a transmission media. The processor-basedcommunications device may be a personal digital assistant, a wirelesscommunications device, or a personal computer.

In another aspect, the present invention comprises a method foroverlapping stored audio elements in a system for providing a customizedradio broadcast. Specifically, the method includes the steps of dividinga first audio element into a plurality of audio element components;selecting one of said audio element components; decompressing theselected audio element component; selecting a second audio element;decompressing the second audio element; mixing the decompressed audioelement component with the decompressed second audio element to form amixed audio element component; and compressing the mixed audio elementcomponent to form a compressed overlapping audio element component. Thecompressed overlapping audio element component may replace the selectedaudio component. The first audio element may be a song, while the secondaudio element may be a DJ introduction.

In yet another embodiment, the present invention provides an audioelement cache. The audio element cache is capable of caching audioelements for each user. In operation, customized radio content isprovided to remote listeners in a personal radio server system by:storing a plurality of audio elements in a file server; retrieving asubset of the plurality of audio elements from the file server bypredicting the content desired by a remote listener based on a userprofile of the remote listener; storing the subset of the plurality ofaudio elements in an audio element cache; selecting audio elements toprovide to a remote listener from the audio element cache; andtransmitting the audio elements to the remote listener. In anembodiment, the plurality of audio elements are stored in the audioelement cache when a remote listener logs-on the personal radio serversystem.

In still another aspect, the present invention provides a method ofgenerating a number audio element for playing a desired number in anaudio system. Specifically, the method sets forth the steps of storing aplurality of audio elements used to represent a subset of the range ofnumbers; defining a plurality of match types used to determine if one ormore matching audio element exists in the subset of the range ofnumbers; defining a plurality of accuracy prefixes representative of theerror associated with any rounding of the desired number to be played;setting the accuracy prefix to a value representing an exact matchbetween the desired number and a number audio element in the storedsubset of audio elements representative of the range of numbers;filtering the audio elements to determine if an exact match exists; ifan exact match does not exist, rounding the desired number to apre-determined level of precision to create an estimated desired number;setting the accuracy prefix to a value representing the error associatedwith any rounding of the desired number to be played; filtering theaudio elements to determine if an exact match exists between theestimated desired number and any of the plurality of audio elements usedto represent a subset of the range of numbers; and repeating the stepsof filtering until such time as an exact match has been determinedbetween the estimated desired number and any of the plurality of audioelements used to represent a subset of the range of numbers. Once anexact match is determined, the number audio element is transmitted to aremote user.

The number audio element of the present invention may be a stock quoteor an announcement of the time. Further, the number audio element may betransmitted in telephone systems, automated teller machines, or otheraudio system.

The present invention takes advantage of a method for efficientlycomparing two trinary logic representations, including the steps ofcreating a first data structure (referred herein as a VALUE datastructure) representative of a first set of properties; creating asecond data structure (referred herein as a KNOWN data structure)representative of whether the first set of properties is known; creatinga third data structure (referred herein as a TARGET data structure)representative of a target set of properties; creating a fourth datastructure (referred herein as a WANT data structure) representative ofwhether the target set of properties is wanted; and comparing the first,second, third, and fourth data structures using bit-wise binaryoperations to determine whether the first set of known properties arewanted as a target set of properties. In exemplary embodiments, thebit-wise binary operation are performed according to the Booleanequation: (not WANT) or (KNOWN and ((TARGET xor VALUE))). Alternatively,the bit-wise binary operation are performed according to the Booleanequation: (not WANT) or (KNOWN and ((TARGET and VALUE) or ((not TARGET)and (not (VALUE))). These data structures may be any size computer word,including 16 and 32-bit words.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention and theadvantages thereof, reference is now made to the following descriptionstaken in conjunction with the accompanying drawings. In the drawings,depicted elements are not necessarily drawn to scale and like or similarelements may be designated by the same reference numeral throughout theseveral views.

FIG. 1 shows a high-level block diagram of the personal radio systemaccording to the present invention.

FIG. 2 illustrates the architecture of a remote terminal for receivingand playing radio broadcasts as part of the personal radio system of thepresent invention.

FIG. 3 illustrates a high-level block diagram of the personal radioserver of the present invention.

FIG. 4 illustrates a more detailed block diagram of the components of anexemplary personal radio server according to the present invention.

FIG. 5 shows a more detailed block diagram of the components of the UserProfile Database (UPDP) according to an embodiment of the presentinvention.

FIG. 6 is a diagram of the records and components in the User HistoryDatabase according to an embodiment of the present invention.

FIG. 7 illustrates an Audio Element Database (AEDB), which contains arecord of the audio elements (e.g., music, disc jockey intros, news;etc.) available to provide to a user.

FIG. 8 shows a more detailed block diagram of the components of an audioserver of the PRS according to the present invention.

FIG. 9 shows a more detailed block diagram of an audio server threadaccording to an embodiment of the present invention.

FIG. 10 shows a block diagram for the Audio Element Selector (AES), itsconstituent Radio Program Clock (RPC) and Audio Element SelectorFunctions (AESF's), and their connections to the Audio Server Thread(AST) and Audio Element Database (AEDB).

FIG. 11 illustrates a portion of the Audio Element Selector (AES)function that relates to the selection of a Disc Jockey Introduction fora song.

FIG. 12 shows a block diagram of the Disc Jockey Song Overlap Scheme(DJSO) according to an embodiment of the present invention.

FIG. 13 shows a more detailed block diagram of the Disc Jockey SongOverlap Scheme according to an embodiment'of the present invention.

FIG. 14 is a flow diagram of the Audio Element Selector Function (AESF),which is responsible for assembling the best audio representation of thecurrent time from the available data.

FIG. 15 illustrates a high-level block diagram of the User CustomizedAudio Element Cache (UAEC) of the present invention.

FIGS. 16a-c show the data structures used in the determination of thecontent to provide a user.

FIGS. 17a-c show the data structures used in the determination of thecontent to provide a user based on the city where the user lives.

FIG. 18 is a diagram of an exemplary exclusion list data structureaccording to an embodiment of the present invention.

FIG. 19 is a graphical representation of the use of an exclusion listdata structure according to an embodiment of the present invention.

While the invention is susceptible to various modifications andalternative forms, specific embodiments thereof are shown by way ofexample in the drawings and will herein be described in detail. Itshould be understood, however, that the drawings and detaileddescription thereto are not intended to limit the invention to theparticular form disclosed, but on the contrary, the intention is tocover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the present invention.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

For purposes of defining the invention, the following abbreviations havebeen used throughout the specification:

PRS Personal Radio System AS Audio Server AES Audio Element Selector FSFile Server DB Database AE Audio Element AEID Audio Element Identifier(also referred to as an “ID”) UP User Profile UPDB User Profile DatabaseUPREG User Profile Registration Record UPDEM User Profile DemographicsRecord UPINT User Profile Interest Info Record UPHIST User ProfileHistory Info Record UPFREQ User Profile Frequency Preference Record UPMPUser Profile Music Preference Record EID Enumeration ID AST Audio ServerThread ASSMQ Audio Server Shared Message Queue ASTFQ Audio Server ThreadFile Queue AEDB Audio Element Data Base AESF Audio Element SelectionFunction UH User History Record US User State UP User Profile DJAESFDisc Jockey Audio Element Selection Function DJAE Disc Jockey AudioElement UAEC User Audio Element Cache DJSO Disc Jockey Song OverlapScheme UPCM User Property Compression Mechanism TRIT Trinary PropertyRepresentation XLIST Exclusion List Representation

The present invention is described in relation to a personal radioserver for providing customized audio content to listeners. Although thepresent invention is described in this context, it should be understoodthat the concepts disclosed herein would also apply to other forms ofservers for providing broadcast content to remote users. For example,the present invention may be used to stream customized video to a remoteuser.

FIG. 1 illustrates a high-level block diagram of the interaction betweenusers 4 a-n with the personal radio server 2 of an embodiment of thepresent invention. The main function of the personal radio server 2 isto simultaneously produce individually customized radio programs forhundreds or thousands of end users. In an embodiment, the personal radioserver 2 comprises a computer program running on a host server. Moreparticularly, an embodiment of the system comprises a C++ programrunning on a Linux operating system on a 500 Mhz Intel Pentium IIIcomputer. A standard SQL back-end (e.g., MySQL or Oracle) is used forthe persistent data storage. In an embodiment, the system is capable ofsupporting approximately 2,000 simultaneous users. Typically multiplesuch systems are clustered to create audiences of tens or hundreds ofthousands. Although a particular embodiment of the personal radio server2 is described using a C++ program with a SQL back end, it should beunderstood that the personal radio server software may be ported toother hardware platforms or architectures without departing from thescope of the present invention.

In operation, the personal radio server 2 provides to each user 4 a-n acustomized radio program that may consist of the following types ofcontent:

the user's favorite music, introduced by a user-selected DJ and in amanner of their choice

talk by a user-chosen DJ (or group of DJs)

news reports on topics that interest the particular user

sports scores and reports for only those teams selected by the user

ski reports for resorts where the user visits

stock reports for companies the user has or wants to invest in

weather in the user's local area

traffic reports only on the routes the user takes

advertisements for products and services that the user wants orfrequently purchases

school closings for only those schools that the user has an affiliation

individual and group contests

reminders that interrupt the running program with a message

automatic alerts which are triggered by changes such as a drop in stockprices the user has, traffic jams on the user's particular routes,severe weather in the user's area, etc.

informational and instructional content about the system itself

“virtual requests” made by other users, but limited to requests forsongs that the current user actually likes

audio elements, such as jingles, that know and use the user's name(e.g., “Hey Fred, this is your radio station”, or “Its time for Fred'sstocks”).

It should be understood that this list of content for the customizableradio system is merely intended to be illustrative. Other content may becustomized and delivered in this manner without departing from thespirit and scope of the present invention.

The personal radio server 2 is attached to a network 6, which isaccessible by many users (4 a-n) through remote terminals. In anembodiment, the network 6 is the Internet, which is accessible by asignificant percentage of the world population. Alternatively, thenetwork 6 may be a local area or limited area accessible network. Users4 a-n connect to network 6 through a processor-based communicationsdevice. Each processor-based communications device includes software forinteracting with the personal radio server 2 and for providingcustomized radio content to the user.

FIG. 2 illustrates a high-level block diagram of the architecture of aremote terminal 12 in an embodiment of the present invention. The remoteterminal is used by the user to access the personal radio server 2. Theremote terminal 12 will generally include a processor 12, a D/Aconverter 14, a speaker 16, a modem 18, and memory 20. In an exemplaryembodiment, these components are part of a personal computer system thatincludes a sound card. Alternatively, these components may be includedin a personal digital assistant (PDA), a cellular telephone, or othersuitable processor-based communications device. The processor 12executes software for providing the personal radio functions to a user.The software executes in memory 20 and controls operation of processor12. In the illustrated embodiment, the radio broadcast signal isdigitally encoded and transmitted to the remote terminal 12 via modem 18over a transmission media. The processor 12 decodes the transmission anddirects all radio broadcast signals to D/A converter 14, which thentransmits the radio broadcast to a speaker 16.

FIG. 3 illustrates a more detailed high-level block diagram of thepersonal radio server system of the present invention. In an embodiment,the personal radio server 2 includes a computer system, or collection ofcomputer systems, consisting of four fundamental components: a streamingaudio server (AS) 32; a highly specialized audio element selector (AES)38; a standard SQL or hierarchical database server managing specializeddata tables (DB) 36; and a file server (FS) 34. FIG. 3 further includesan indication of data flow between each of these components.Specifically, database 36, or other data management system, includesuser (listener) profiles (UP). These profiles provide the audio server32 with specific information about the type of content to broadcast tothe remote listener. The audio server 32 also interfaces to the audioelement selector (AES) 38 and provides a particular user's current userstate (US). The AES 38 uses the information provided from the userprofile (UP) in database 36 and the current user state (US) to selectthe appropriate content to provide to the audio server. The database 36also includes audio element records that identify the audio elementsstored in the file server 34. Thus, the AES 38 selects and retrievesaudio element identifiers from database 36. Then, the AES 38 providesthe audio element identifier (AEID) to file server 34. The file server34 selects the appropriate audio element (AE) that includes the desiredcontent and provides it to the audio server 32 for transmission to theremote user. After providing the audio element to the remote user,database 36 is updated with a log entry to indicate the last audioelement transmitted to the remote user 4. Each of these components isdescribed in further detail below.

FIG. 4 illustrates a more detailed block diagram of the components of anexemplary personal radio server according to the present invention.Sections 1-4 below discuss further details relating to each component ofthe system.

1. Streaming Audio Server (AS)

The streaming audio server (AS) module 32 interfaces with the end user4, the AES 38, DB 36, and the FS module 34. In operation, when the user4 logs-on to the system, the software on the user's computer system,network appliance, or portable wireless-networked device initiates aconnection to the AS module of the personal radio server. The user'ssystem then requests the radio program for that end user using astandard communications protocol such as HyperText Transfer Protocol(HTTP).

The AS module 32 then communicates with the DB module 36 to retrieve theuser profile (UP) and the last user state (US) for the appropriate userfrom the UPDP 46. If the user has no profile (i.e., the first log-on forthe user), a new UP is created and the user is issued a new useridentification code and the US is set to a default initial condition.Next, the AS module 32 passes the user state and profile to AES module38. It should be noted that in alternate embodiments the AES 38 mayrequest the UP directly from the DB module 36. After receiving the UPand US, the AES module 38 then uses the US and the UP to determineexactly which audio element or elements should be sent to the end user.With this information, the AS 32 requests the file(s) corresponding tothe audio element(s) selected by the AES 38 from the FS 34.

The AS module 32 then transmits, via streaming or other suitable methodof transmission, those files to the end user's system at the appropriatebit-rate. When the files have been almost completely streamed to the enduser, the AS 32 requests additional audio elements from the AES 38 andthe process continues so that the stream to user 4 is uninterrupted.

Although the present invention is illustrated using streaming data, itshould be understood that other forms of transmitting audio content to aremote user may be used without departing from the spirit and scope ofthe present invention.

2. Audio Element Selector (AES)

The audio element selector (AES) module 38 is a highly specialized pieceof software that interfaces with the AS 32 and the DB 36 modules.Internally, the AES module 38 includes a radio program clock (RPC) 40and a series of special audio element selection functions (AESFs) (42a-n). The RPC 40 determines what type of audio element should be sent tothe user next. Under control of the RPC 40, the audio element selectionfunctions (42 a-n) select the audio elements of each type that should besent to the end user. In an embodiment of the invention, one audioelement selection function exists for each type of audio element. Forexample, audio elements may include

songs

introductions

news

traffic

weather

sports scores and game reports

stock prices, news

jingles and station identification

advertisements

school closings

reminders

instructions

time

date

talk/morning show

serialized radio programs

The RPC 40 is designed to choose audio element types to achieve thefrequency specified in the particular user's profile. For example, theuser's profile may indicate that news should be played twice an hour,sports should be played once an hour, while traffic should be providedat the end of each hour. The user may manually select these userpreferences. Alternatively, the user profile may be determined by usingcollaborative filtering, or selected by a radio programmer. The RPC isdesigned to optimize the radio program to have all the content typeswith the appropriate frequency, and to resolve conflicts when two typesof content are supposed to occur at the same time (e.g., news andtraffic report). The output of the RPC is the particular content typethat should be sent to the end user next.

After determining the particular content type, the AES 38 runs the AESF(42 a-n) that corresponds to the content type chosen by the RPC 40. EachAESF (42 a-n) uses the user's profile and past listening history toselect from the DB module exactly which audio elements should be sent tothe end user. The AESF insures that disallowed combinations of audioelements are not played too closely in time. For example, the AESF maybe programmed to prevent repeating the same news story, playing the samesong, unintentionally playing songs by the same artist, and playing anad for a product right after an ad for a competitive product. In anembodiment, this function is provided through the use of “ExclusionLists” or “XLISTs,” which may include one or more exclusion lists pertype of audio element. The list stores the last N elements of that typewhich were played (where N is selected as appropriate). Information onthe exclusion list is maintained as a queue. As new elements are added,the oldest elements are removed. The AESF can then check that for eachnew audio element whether the selected audio element matches certainproperties of past audio elements (such as the artist in the case ofsongs). The XLISTs differ from the UHDB in that XLISTs may be formedover different types of audio elements. For example, an XLIST may becreated based on the artists played to a particular listener to preventhearing the same artist within a predetermined number of songs. Otherexamples of XLISTs that may be created are for artist gender to ensurevariation of artist gender from song to song.

In addition to determining whether the particular combination of contenttype is appropriate, the AESF (42 a-n) guarantees that the selectedaudio elements are appropriate for the end user (i.e., the user'spreferred DJ, the users desired stocks, etc.). In some cases, the AESFcomposites multiple audio elements to generate the desired audio (i.e.,the stock price “123⅝” may actually be represented by audio elements“123” and “⅝”). Alternatively, the audio may actually be represented inan alternate format. For example, the stock price of “123⅝” may berepresented by multiple audio elements in an alternate format (forexample, the audio elements may include “almost,” “124, ” and “¾, ” oreven “about” and “125”). For a more complete description of the softwarefor performing this type of alternate representation format, see FIG. 14and the accompanying discussion.

3. Database (DB)

In an embodiment, the database module 36 consists of a standard SQL orhierarchical database. It should be understood, however, that any datamanagement system may be used without departing from the spirit andscope of the present invention. Within the data base, several datatables are maintained: an audio elements database (AEDB) 44, a user'sprofile database (UPDB) 46, and a user's history database (UHDB) 48.

The Audio Element database 44 includes one or more tables 36 thatenumerate the “meta-properties” for each of the audio elements stored inthe FS module. A “meta-property” is additional information that may beassociated with an audio element, including information related to:

the type of audio element

the date the audio element was recorded

the expiration date for each audio element

the jock who recorded the audio element

the city referred to in the audio element (if any)

the user name referred to in the audio element (if any)

the product type being advertised in the audio element (if applicable)

the artist who performed the song contained in the audio element (ifapplicable)

the artist who wrote the song contained in the audio element (ifapplicable)

the companies referred to in the audio element (if applicable)

the sports teams referred in the audio element (if applicable)

These meta-properties allow the DB 36 to select only that content whichis appropriate for a given user, content-type, and situation. Forexample, some of the meta-properties associated with a news audioelement are Type, City, and DJ. The DB module can be used by the AES tofind all news elements that have a Type that the user is interested in,have a City that matches the user's home city, and have been read by theuser's preferred DJ.

4. File Server (FS)

A standard file server 34 or any dedicated network data storage devicemay be used for storing the audio elements. In an embodiment, files onthe file server are organized for rapid retrieval by the AS when giventhe audio element identification retrieved from the DB 36 and chosen bythe AES 38. Each audio element (AE) is stored as a compressed audiofile. In an embodiment, AE's are stored in MPEG I Layer 3 (commonlyknown as MP3) format at 20, 48, 64 and 128 kbps. Each AE may includebetween 0.25 seconds to 3 minutes of content depending on the type ofAE. For example, a “company name” AE may be 2 seconds long, but a longnews story may be a minute. Similarly, “song” AE's may be severalminutes long.

FIG. 5 shows a more detailed block diagram of the components of the UserProfile Database (UPDB) 46. According to an embodiment of the presentinvention, for each user of the system, a Dynamically Adaptive UserProfile (DAUP) (50 a-n) (also referred to as the “UP”) is stored withinthe database 46. The DAUP (50 a-n) is a data structure stored in the DB36 and used by the AES 38 to select the content that is most appropriatefor the particular user based on the data stored in the user profile.This data may include, but is not necessarily limited to, data relatingto a user's preferences for particular songs, types of news (e.g.,international, business, etc.), or particular sports teams. Eachlistener's DAUP is dynamic in that the information in the databasechanges gradually as the user volunteers information about his or herpreferences. The user can provide this information in many ways. Forexample, the listener may be able to dynamically rate a record orproduct via a web page during the transmission of a related audioelement such as a song or advertisement as described in more detailbelow.

As shown in the exemplary embodiment in FIG. 5, each entry in the DAUP50 may be divided into several components: initial registrationinformation (UPREG) 52, information on content balance and frequency(UPFreq) 59, information on demographics (UPDEM) 56, information oninterests (UPINT) 58, information on music preferences (UPMP) 60, andinformation on the user's profile history (54). When the user first logsin, the UPREG 52 for the DAUP is derived from a small set of initialquestions. In an embodiment, the user is asked for his first name and anidentification of “radio station” from a list of available formats. Forexample, exemplary radio formats may include “80's rock” or“contemporary country.” Both at the initial log in, and subsequently,the user may specify additional properties. For example, the user mayinitially be requested to identify their zip code, preferred greeting(i.e., a first name or nickname), gender, age, favorite sports teams, orstock watch list.

The UPFreq 59 portion of a UP entry 50 in the UPDB 46 containsinformation relating to the content the user prefers in a radiobroadcast. According to an embodiment of the invention, the user maycontrol the balance between different content types by modifying theinformation in the database. The UPFreq 59 is a record within the DAUP50 that takes the form of a set of frequencies—one frequency for eachcontent type. For example, the non-advertisement portion of thebroadcast might be divided to provide 80% music, 10% talk, and 10% newsduring a radio broadcast. In an embodiment, the user may not control thefrequency of the advertisement portion of the broadcast. For example, anexemplary system may require the PRS to provide a user with 8advertisements per hour.

In an embodiment, the user may be provided direct control over thesefrequencies via a web page. Alternatively, the user can be asked toselect from a set of alternatives such as “mostly music, not much talk,”“lot's of jokes, and stories,” “serious listener, introduce and describethe songs,” “extra sports news,” or “more traffic and weather please.”In each case, the frequency of content type may be tailored to bettersuit the particular listener.

The UPDEM 56 portion of the database stores demographic informationrelating to each user. For each user, the AESF 42 that corresponds tothe particular user will tailor advertisements (and some other types ofcontent) to the particular demographics of the user. For example, theAESF may provide a commercial for luxury automobiles to a user thatlives in a particular zip code, while the AESF may select a commercialfor pick-up trucks to a different zip code. In an embodiment, the UPDEM56 is a record within the DAUP 50 that takes the form of a set of binaryand enumerative variables. The UPDEM 56 represents conventionaldemographic information about the user such as income, city, sex, age,etc. The UPDEM 56 may also include other information that is designed tohelp the PRS target content to a user based on the user's demographics.For example, other information that may be included in the UPDEM 56includes categories such as “interested-in-purchasing-computer,” “carowner,” “home owner,” etc. In an alternate embodiment, the user may beable to edit the information in the UPDEM through a user interface. Inaddition, the PRS may incorporate demographic information relating to alistener from a secondary source such as “Double-click” or “Engage.”

The UPHIST 54 portion of the UP stores the history of the user's states.In particular, the UPHIST may be used to retrieve the last User State(US) for a particular user when the user logs into the system.

The UPINT 58 portion of the UPDB 46 allows the user to specify a list of“interests” that relate to topics that the listener would like to hearmore about. In an embodiment, the UPINT 58 is a dynamic length list. TheUPINT stores a list of the user's favorite sports teams, stock holdings,roads used to drive to/from work, favorite vacation destinations, etc.This information is used to further customize the PRS broadcast. Forexample, the user may specify a particular interest in a few sportsteams. Based on this information, the sports news segment broadcast to aparticular user will mention only those teams in which the user isinterested. In addition, a stock report may be tailored to give theprices of the user's stock as well as news reports that bear upon theparticular stock. Similarly, the traffic report may only report delayson roads used by the particular user. The weather report may beconfigured to only mention local weather, as well as the weather in theuser's favorite vacation spot. In an embodiment, the user's interestinformation is developed by allowing the user to select from among achecklist of choices.

Alternatively, the user's interest information may be obtained byallowing the user to navigate through a directed acyclic graph (DAG) ofinterests. The DAG includes interests in a parent-child hierarchy. Forexample, “Yankees” may have “New York City” and “baseball” as parents,and “Steinbrenner” and “Babe Ruth” as children. A user could choose toadd any of those to their interests, or could edit any of the parent orchildren elements. For example, by selecting “New York City,” the userwould be allowed to pick from its parents—New York State, “state,” “bigU.S. cities”} and its children—(“Statue of liberty,” “Manhattan,”“NYSE,” “Wall Street,” etc.).

The UPDB 46 may also include the user's music preferences in a separateportion of the database called the UPMP 60. The UPMP stores song ratingsentered by the user. Ratings from many users may be combined to predictratings for new music, a process known as “collaborative filtering.”Collaborative filtering involves storing a dynamic set of recordsassociated with each user, one record for each rated song, and based ona small set of user song ratings stored in the UPMP 60, the user'srating of other songs may be predicted. In operation, the collaborativefiltering process works by comparing a user's ratings to the ratings ofother users in the database. If two users generally agree on many songs(i.e., the users both either dislike or like the same songs), then theyare likely to agree on other songs. Thus, the PRS can predict, based onusers with similar tastes in music, how a user will rate a song. Thus,based on this information, the PRS may select the content for aparticular user based on this collaborative filtering process.

In an embodiment of the collaborative filtering system of the presentinvention, the PRS system 2 will utilize data from a group of paidraters, referred to herein as “trendsetters.” The trendsetters may bepaid to rate many songs in their area of interest. Each trendsetter willbe compared to the current user. Thus, based on the trendsetter, ortrendsetters, that are most similar taste to the user, the PRS maypredict the future user ratings. In an embodiment, the AESF may beconfigured to select songs for a particular user that are highly ratedby those trendsetters that most closely represent a user's interests.

To further support the collaborative filtering process and the gatheringof information for each user's UPDB 46, a user may provide feedback on asong by song basis. For example, in an embodiment, the present inventionincreases the amount of user feedback by adding software or hardwarebuttons to the playing device. These buttons may include feedbackinformation such as “Great Song!,” “Pretty Good,” “OK Song,” “Not sohot,” and “Yuk, don't play that again.” Thus, the displayed softwarebuttons allow the user to easily rate the currently playing song.

In some cases the user may be unwilling to give song-by-song feedback.One format for painless feedback is the station change button of agraphical user interface of the present invention. According to anembodiment, at any point during a broadcast session, the user will beable to “change stations,” either to another format, or to a similarformat which is in a different state (i.e., perhaps playing a differentsong). The UPMP 60 stores data relating to this station change behaviorand attempts to find a correlation with particular songs.

Although the feedback process and the collaborative filtering processare discussed in relation to music content, it should be understood thatthe feedback process may be used for any type of content. For example,this feedback process may be used to select various talk shows,advertisements, or other types of audio elements.

FIG. 6 shows a more detailed embodiment of the user history database(UHDP) 48. In an embodiment, the UHDP 48 includes user history recordsfor every user of the system. Each user history (60 a-n) includes datafor the user of the system relating to the broadcast content received bythe user while logged-in to the system. In an exemplary embodiment, eachset of user history records (60 a-n) is organized in a hierarchicalmanner such that each user history includes records relating to thevarious “types” of content (e.g., news, music, etc.) (62 a-n) providedby PRS. Within each “type” record, a record is maintained for the timethe particular content was played, and an identification number (“ID”)for the particular broadcast content. In this manner, the UHDP maintainsa record of all audio elements played to a user, and when the audioelement was played.

By maintaining a list of all audio elements played, and when theelements were played, the present invention may customize futurebroadcast content based on past listening patterns. For example, if theuser continually interrupts their audio program to jump to the trafficaround 4:30 p.m., the system may automatically schedule transmission tothat user of an audio element that includes traffic information at 4:30p.m. Other examples arise from more subtle trends. For example, if theuser tends to give positive feedback for mellow songs and negativefeedback for active songs in the morning, and then does the reverse inthe afternoon, the system may automatically vary the distribution ofmusic accordingly.

FIG. 7 illustrates another component of the DB 36 according to anembodiment of the present invention. Specifically, DB 36 includes anAudio Element Database (AEDB) 44 that contains a record of all the audioelements (e.g., music, disc jockey intros, news, etc.) available toprovide to a user. In an embodiment, the AEDB 44 consists of a number ofaudio element records (70 a-n) stored by the type of audio content. Eachaudio element type record includes a number of audio elements (72 a-n)of the same type. For example, the audio elements may includeintroductions for a particular song from a number of different discjockeys.

In an embodiment, each audio element (72 a-n) may include an ID 74, atype 76, one or more enumeration ID's (78 a-n), and a binary propertylist 79. The ID 74 provides a unique identification number for eachaudio element. The type 76 provides information relating to the type ofcontent in the audio element. Each audio element may include one or moreenumeration ID's (78 a-n), which identify the particular demographicinformation to which the audio element pertains. For example, the EIDmay include an indication of a city to which the audio element pertains(e.g., a weather forecast for the city of Austin). Additionally, theaudio element may also include many “yes/no”-type binary properties 79.These properties can be efficiently stored and compared using a specialmechanism called the TRIT representation, described below. Theproperties 79 of the audio elements allow the DB 36 to filter outcontent that is not appropriate for a particular user. In addition tothe “city” EID, other exemplary EID's may include the user's favorite DJor type of news.

FIG. 8 shows a more detailed block diagram of the components of an audioserver 32 of the PRS according to the present invention. Each user 4interfaces to the PRS via a network 80. Once again, the network 80 maybe the Internet, a WAN, or any other suitable transmission media. Allcommunication with the running system occurs via a standard web server(WS) 82 or an alternative input/output portal. The web server negotiatesuser interface and input verification. Information that needs to bepassed to the running AS is passed into the AS shared message queue(ASSMQ) 84. The ASSMQ listens for connections from the WS. When aconnection is received, one of several messages can be passed to theASSMQ. Such messages include “skip to next element,” “song feedback,”“jump to traffic,” etc. The ASSMQ is then queried by the individualAudio Server Threads (ASTs) that are executing for each user. Each ASTchecks the queue for messages destined for the program it is generating.When a message is found, it is removed from the queue, and theinstructions are followed by the AST, potentially causing modificationto the course of the audio stream. For each user that has logged in tothe PRS, the audio server 32 creates an audio server thread (AST) 86a-n. Each audio server thread is a separate process executing in theaudio server 32. An audio server thread is responsible for maintainingand managing each radio broadcast session for a user by communicatingwith the DB 36, the AES 38, and FS 34.

FIG. 9 shows a more detailed block diagram of an audio server thread(AST) 86. The AST is typically composed of 4 parts: a connection 95, aUser State 90, a File Queue 92, and a File Buffer 93. Within each AST, aconnection 95 is maintained with the end user using some transmissionmedium. In a preferred embodiment, this medium is wired or wireless IP;however, any other communications medium and protocol can be used. Alongthis connection, the uninterrupted stream of compressed audio istransmitted to the user. Each AST maintains a User State (US) 90 for theconnected user. Within that state, information about the userspreferences and the users listening history, are maintained. Uponinitial connection, the user profile information for that user isgathered from the UPDB 48. Information about the user's prior listeninghistory is gathered from the UHDB 46, and as the user receives newaudio, this is incorporated into the users listening history. Upontermination of the listening session (i.e. when the user ‘logs off’),the listening history from that session is added to the UHDB 48. Duringthe listening session, the AST passes the current user state to theaudio element selector (AES) 38, which uses that information to selectaudio elements (AE's). The selected AE's are then passed back to the ASTwhere their associated filename is queued in the File Queue. File namesare then sequentially pulled off the File Queue, and the files are readin from the file system (FS) and buffered in the File Buffer 93. TheFile Buffer 93 is then sent across the connection 95 via a transmissionmedium to the end user. As the File Buffer 93 empties, another filenameis pulled off the File Queue. When the File Queue empties, anotherrequest is made to the AES.

The AES 38 is shown in detail in FIG. 10. The AES selects an appropriateaudio element by first choosing the type of audio element, then bycalling the appropriate constituent Audio Element Selector Functions(AESF's) in the AES 38 to select the AE from the AEDB. First, the RadioProgram Clock (RPC) within the AES uses the current User State (US) 90and User Profile (UP) from UPDP 46 to determine the next type of AE tosend to the user. The RPC bases its decision upon the current US (whichcontains information about how many times each type of AE has been sentto the user) and the UP (which contains user preference informationabout how many times per hour the user wants each type of AE sent tothem). The RPC then determines the next AE type to be sent to the user.When multiple types of AE's are appropriate, an embodiment of theinvention uses a static preference ranking over AE types to determinewhich AE type to send. Other possibilities for resolving this situationinclude random selection or user set priorities. Once the RPC has chosenan AE Type, the AES executes the appropriate AESF. The AESF then usesthe UP to select AE's that are appropriate for the user. The AESF thenremoves AE's that are excluded by the XLISTs in the US. The AESF selectsone or several AE's and sends their ID's to the AST, where they arequeued in the AST File Queue (ASTFQ) 92 for sending to the user asdescribed above.

FIG. 11 illustrates another aspect of the PRS System, and specifically,a portion of the Audio Element Selector (AES) function. In anembodiment, the AES is configured to provide a Disc Jockey Audio ElementSelection Function (DJAESF). Specifically, FIG. 11 provides a high-levelblock diagram of the AESF providing a disc jockey (DJ) intro to aparticular song. Although the AESF is being illustrated as a DJ introusing the DJAESF, it should be understood that other types of audioelement selection functions may be created without departing from thescope of the present invention. For example, other audio elementselection functions may include the selection of news introductions,song “outroductions” (which follow the song), or other suitable audiosegments.

As illustrated, the DJAESF is a software system that allows for thecreation of a radio program in which particular music and informationalcontent may be chosen independently of the DJ who introduces thebroadcast content. In other words, a given user may control the music,news, and advertisement content through the user's profile, andindependently select the DJ that the user wants to introduce thecontent. In this manner, the user can customize the radio broadcast byselecting the DJ. And because the DJ is an integral part of any radioprogram, providing the “glue” that holds the program content together byintroducing songs, news segments, time, weather, and other components,the radio broadcast becomes more personal. Accordingly, the user buildsa personal affinity to radio programs created by the personal radioserver.

The various DJ audio elements (DJAE's) are stored within AEDB 36 and FS34. For example, DJAE's may include audio elements relating to SongIntroductions, Song “Outroductions” (which follow the song), NewsIntroductions, News Wrap-ups, Jokes, and other audio segments likestories, serialized “shows” (i.e. the morning show), and various othertypes of audio elements. Unlike conventional radio broadcasts, the DJAEare recorded by the DJ off-line, before the construction of the personalradio broadcast. In the case of song introductions, jokes, introductionof news, and some other segments, these DJAE's may be recorded well inadvance. In the case of more topical content like serialized shows, theDJAE's may be recorded that morning or a few days before. Still othertypes of content, like news stories, may be recorded just beforebroadcast.

In operation, the DJAESF selects the appropriate DJAE from the DB (e.g.,a particular song should be preceded by an introduction of the song, theoutroduction of a particular song, etc.). This selection is made basedupon the type and specific content of the DJAE.

In an embodiment, information about each DJAE is represented in auniform fashion across DJ's. For example, in the case of a songintroduction, the information about the recording DJ, the song, and thetype of introduction is stored with the DJAE. When selecting anintroduction to precede a given song, the DJAESF is free to select aDJAE that matches the song and introduction type. In this manner, theDJAESF may easily replace one DJ for another throughout the broadcast.

The user may specify his or her DJ preference either by selecting from afixed list of available DJ's or by providing generic information aboutthe user's DJ preferences. This information is then stored in a userprofile. This mechanism is more general than a simpler scheme in whichthe user simply selects a particular DJ. For example, a classical musiclistener may wish to hear very detailed historical descriptions of eachclassical piece. It may not be the case that any single DJ has recordedthe detailed historical introductions for every classical piece that maybe broadcast. However, the DJAESF may use the user's profile informationto select an introduction based on the “type” of DJ desired rather thana specifically selected DJ.

Once again, FIG. 11 illustrates a specific application of the DJAESF.Specifically, FIG. 11 describes the high-level operation of theselection of a DJ introduction to a song according to the DJAESF of thepresent invention. Specifically, the DJAESF 110 includes a DJ Matcher112 and an Introduction selector 114. The DJ Matcher 112 is a filteringfunction that eliminates from contention all AE's that do not have anappropriate DJ introduction as per current user's preferences (stored inUPDB 44) and the music content that is going to be played (as stored inthe AEDB 36). Once the remaining set of appropriate introductions isdetermined, the Introduction selector 114 selects the DJ introductionfrom the AEDB 36. The introduction is then sent to the AST where it isplaced on the AST File Queue (ASTFQ). The Music Ranking Generator 113 inFIG. 11 is the portion of the system that computes a songs rating basedon collaborative filtering.

In an alternate embodiment, the PRS may be configured to play the DiscJockey introduction or “outroduction” over the beginning or end of asong. FIG. 12 shows an embodiment of the Disc Jockey Song Overlap Schemeof the present invention. Specifically, the DJSO 120 comprises acomputer software program for constructing, compressing, anddecompressing audio files; a database for storing compressed audiofiles; and the software necessary to stream audio files. The motivationfor DJSO is that in conventional radio broadcasts, the DJ normally“talks over” the beginning of songs by introducing the song or theartist. Alternatively, the DJ will talk over the end of a song in orderto transition to new content. In an embodiment of the PRS, the DJAE'smay be pre-recorded with the combination of the introduction andbeginning of a song. The newly created DJAE may be stored as a new typeof ALE (e.g., a DJ introduced song (“DJS”)). However, the total numberof DJS AE's is the product of the number of DJ's and the number ofSongs. Thus, the storage of the combined audio elements is only feasiblewhen there are relatively few DJ's (or few songs). For example, if thePRS supports approximately 100 DJ's and 10,000 songs, the combination ofDJ's and songs would require the storage of 1,000,000 DJS AE's that arerecorded and stored separately from the Songs AE's. Once again, theseALE files may be stored in a compressed format (e.g., MP3 or RealAudio).Even so, a significant amount of storage is required to store each songwith an overlapping of the DJ introduction (or “outroduction”).Accordingly, a need exists for a method of combining a DJ introductionwith a song audio element file without having to record a large numberof DJS AE's.

In an embodiment, the DJSO 120 in FIG. 12 eliminates the need to recorda large number of DJS AE's. One potential solution to this problem wouldbe to simply mix the audio of a song AE with the audio of a DJintroduction ALE at the time of the broadcast. This avoids the massiveduplication of songs described above. However, given the compressed filerepresentations of these audio elements, it is very difficult to mix(combine) the audio from the DJAE with the song AE (so that the two canbe heard at the same time). Therefore, in an embodiment of the PRS ofthe present invention, the system may first uncompress the files, mixthem as uncompressed files, and then re-compress. Although this solutioneliminates the need for a large amount of storage, the re-compressionstep requires a great deal of computation. Typically, compression is farmore expensive than decompression. Compressing a 3-minute song takesapproximately 3 processor minutes on an Intel Pentium III 700 MHzprocessor. As a result, compressing a single audio stream requires 100%of the processing power of a single processor. Thus, given that the PRSsystem may handle up to 100,000 users in an embodiment of the invention,it is infeasible to dedicate 100,000 processors dedicated to thisre-compression function.

The present invention overcomes some of these problems by providing aDJSO 120 as shown in FIGS. 12 and 13. The DJSO pre-computes the audiocreated by mixing the DJAE and the Song AE; the result may then becompressed and stored for rapid retrieval and immediate use later. Inoperation, the DJSO first divides and decompresses (at block 133) eachcompressed song audio file 122 into three components: a HEAD 130, a TAIL131, and a BODY 132. The HEAD is the beginning portion of the song 134.The BODY is the middle portion, and the TAIL is the end of the song.Similarly, the song Intro 135 is decompressed at block 136 to form asong introduction. Each of these portions is compressed separately atcompressor 138 so that when the HEAD, TAIL, and BODY are concatenatedand streamed together, the user's audio player plays the entire song inan unaltered manner. Note that the concatenation operation is verysimple, in that the AES need only play the HEAD AE, followed directly bythe BODY AE, and then the TAIL AE. This operation is computationallytrivial, requiring almost no processing time. As a result theconcatenation of these files can be done for 1000's of simultaneoususers on a single computer.

Additionally, the song components are defined so that the BODY portionof the song is never overlapped (“talked over”) by any Jock. In otherwords, the HEAD portion is longer than the longest DJ introduction AE124 for any particular song. Similarly, the TAIL is longer than thelongest JOCK outroduction 126. In an embodiment, the length of the HEADand TAIL for all songs can be set to be the same constant amount of time(perhaps 5 seconds). Accordingly, this limits the length of the longestoverlap between DJAE and a song introduction AE, but it simplifiesprocessing. Further, because the BODY is never overlapped by any DJAE itcan be stored separately as a compressed Song BODY AE 128 independent ofany introduction or outroduction. In addition to the BODY AE, for eachsong, one new AE is generated for each DJ introduction. Thisintroduction AE is created by mixing the uncompressed versions of theHEAD and the DJ introduction to form a Song/Intro AE. Then, the resultis compressed and concatenated with the BODY and TAIL to yield an audiostream in which the beginning of the song is mixed with the introductionwhile the end is unaltered. In addition, for each song, one new AE isgenerated for each DJ outroduction. This outroduction AE is created bymixing the uncompressed versions of the TAIL and the DJ outroduction.The result is then compressed so that it can be concatenated with theHEAD and BODY to yield an audio stream in which the end of the song ismixed with the outroduction to form a compressed Song Tail/OutroductionAE 129. In addition, the compressed song tail AE 125 may be stored forusers who do not want any DJ audio elements.

Similar to the previously described system, the DJSO function 120requires the duplication of AE's. An important advantage is that theBODY portion of each song need not be duplicated. The BODY portion isoften more than 90% of the song, and as a result, 90% of the duplicationis eliminated. Accordingly, the DJSO requires significantly less diskspace to maintain the AE's.

Although this aspect of the invention is illustrated using DJ audioelements and Song audio elements, it should be understood that thisaspect of the invention may be used to create other types of overlappingaudio elements using any of the available audio elements. For example,the audio element overlap scheme of the present invention may be used tooverlap a user specific reminder over a song audio element.Alternatively, a time audio element may overlap any other audio elementsto allow the time to be announced at particular intervals during abroadcast (e.g., every hour).

FIG. 14 illustrates another aspect of the present invention in which thenumber of Audio Elements required to be stored may be reduced.Specifically, the present invention contemplates the automatic assemblyof numbers to form stock prices, dates or times when exactly matchingaudio does not exist; thereby reducing the number of audio elementsneeded to be stored in order to state stock prices, or alternatively,announce time. For example, there are approximately 1440 possiblecurrent time announcement audio elements that could be required if everytime had to be recorded separately, (i.e., “12:00”, “12:01”, “12:02, ”etc. One simple solution which exists in the prior art today is torecord hours and minutes separately, and then composite them to producea time i.e., “12”+“00”, “‘12’”+“‘01’”, “‘12’”+“‘02’” etc.) This may bedone with 84 recordings (assuming the hours 1-24 are different audiothan the minutes 1-24). While minimally functional, such a system doesnot produce high quality audio, and does not produce times in the waythat people are used to hearing them. The current invention contains asystem for assembling time and number audio in a more natural way, whileallowing for the incorporation of exact-match audio when it isavailable. While presented in the context of the PRS, this invention hasmany uses beyond PRS. Specifically, this aspect of the present inventionmay be used in any audio system, including phone banking and phoneinformation systems, automated teller machines, or any similar audiosystem that requires the generation of audio elements that representnumbers.

Turning to FIG. 14, a program flow diagram is shown illustrating thetime audio generation feature of the present invention. This featureresults in a reduced number of audio elements that must be stored in theAEDB 44. The system acts to retrieve the exact time when thecorresponding audio element is available, but otherwise combines aseries of time AE's in order to construct an approximate timeannouncement.

First, at step 140 the AE's from DB 36 pass through a DJ Filter, whicheliminates all AE's that are not recorded by an appropriate DJ asindicated in the UPDB 46. The current system time 141 is then convertedin step 142 into the user's local time zone based on informationcontained in the UPDEM 56 of the UPDB 46.

Next, the type of match is selected in order of priority. For a timeaudio the types of matches are EXACT HOUR-MINUTE, MINUTE-HOUR,MINUTE-HOUR+1. In the next step at 144, the time is rounded to thehighest precision used by the system. The Accuracy Prefix is then set toNOW in step 155. An embodiment of the invention has minutes as itshighest precision, but other levels of precision could be used (e.g.,more precise(seconds) or less precise (every 5 minutes)).

The match type is then used to select a filter that eliminates all AE'sthat do not match the time with the method indicated. At step 146, theAEDB is checked for EXACT matches. In order to have an EXACT match, theAE must contain audio that completely describes the time (i.e., “quarterafter three’”). Similarly, at step 148, the system checks forHOUR-MINUTE filter match AE's that describe the hour proceeding a minuteand a minute following an hour (i.e. “‘three’” “‘fifteen’”). If no matchis found, the system in step 151 checks for MINUTE-HOUR filter matchAE's that describe the minute proceeding an hour and an hour following aminute (i.e., “quarter after” “three o'clock”). Finally, in step 154,the MINUTE-HOUR+1 filter matches AE's that describe the minuteproceeding the upcoming hour and the upcoming hour following a minute(i.e., ‘quarter to’ ‘four o'clock’).

If there are AE's (or AE's pairs in the case of audio composition) thatpass through the filter, then the ASTF is finished, and the AccuracyPrefix and one of the selected time AE's (or pair of AE's) are passed tothe ASTFQ 92. If no AE's pass though the filter, then the time isrounded to the next level of precision at step 144. In an embodiment,the increments in steps of rounding are 5, 10, 15, 20 and 30 minutes. Inan exemplary embodiment, the rounding precision preferences need not besorted in order of precision. For example, rounding may be done to thenearest 15 minutes before rounding to the nearest 10 minutes. Afterrounding, the actual user time is compared to the rounded user time. Ifthe actual user time is less than the rounded time, the Accuracy Prefixis set to BEFORE; if it is greater, then the Accuracy Prefix is set toAFTER. Computation then resumes at step 146.

Steps 144-156 are repeated until such time as appropriate audio elementsare selected. In the unlikely event that still no match is found, thenthe Time AESF fails. This will only happen though in the data-poor casein which there are virtually no time AE's in the AEDB.

In alternate embodiments, the present method may be used for numberssuch as stock prices. With stock prices, precision may be consideredmore important than audio quality. In an exemplary embodiment involvingstock prices, match types of EXACT, DOLLAR-FRACTION,HUNDREDS-TENS-ONES-FRACTION may be used along with the accuracy prefixesof EXACTLY, UNDER, and OVER.

FIG. 15 illustrates an alternate embodiment of the present inventionthat includes a User Customized Audio Element Cache (UAEC) 150. The UAECincludes a memory data structure and the software necessary to retrieveand store cached audio elements for a particular user. After each userlogs in, the UAEC stores a large percentage of the audio elements thatthe user may want to listen to over the course of a predetermined periodof time (e.g., one hour). The cached AE's may include songs,introductions, outroductions, advertisements, news reports, DJAE's (suchas jokes/stories), and other appropriate AE's. These AE's are determinedby the particular user's AESF that is running in the AES 38. The AESFfor the particular user selects the AE's to cache based on the userprofile database 46 and user history database 48.

By caching the AE's, the UAEC may reduce the load on the DB by severalorders of magnitude. In an exemplary system, based purely on bandwidthissues, the PRS may support 100,000 users with approximately 50 audioservers. In this embodiment, each user consumes 20 kilobits per second(kbps) of bandwidth. A simple Linux server handles well over 40 megabitsper second (Mbps) (disk bandwidth is 400 Mbps and network bandwidth isup to 100 Mbps). Therefore, each Linux server can easily handle thebandwidth required for audio streams for approximately 2000 users. Given2,000 users, there will be 2,000 different audio segments retrievedevery 15 seconds (because the average AE is 15 seconds, and there arepotentially 2,000 users per server). As a result, the PRS must play onaverage 6700 unique segments per second. No single database server couldhandle this many requests. Further, most distributed database systemscould not handle this load. For example, given 1000 servers in the PRS,there would be approximately 100 users per machine, making approximately6.7 transactions per second—approaching the limit of high performancedatabase systems that are available today.

Using the UAEC, the number of transactions per second required tosupport the maximum number of users may be reduced by a factor of twohundred. This dramatic reduction is achieved by caching (or pre-fetchingand storing) approximately one hour's worth of audio elements when theuser logs into the system. Most of what the user will want to hear isstatic audio content (songs, introductions, ads, etc.). Because theuser's preferences and history are known at login and will not changesignificantly in the course of an hour (at least not in a typical hour),the UAEC can accurately predict the AE's that may be required in thefuture.

In operation, the caching process utilizes the AESF to select not justthe next AE to be played, but the next N AE's that will be played ofeach type (where N is a large number determined by the system designer).In an exemplary embodiment, one hour of AE's is cached, resulting inapproximately 240 AE's (each approximately 15 seconds) being cached foreach user. Similar to the operation without a UAEC, each user's AESFexecutes queries against DB 36. Each query returns AE's suited to thecurrent user's profile and usage history.

In an alternate embodiment, rather than return a single set of AE's,many different sets of AE's are returned. For example, AE'scorresponding to the best 100 songs that relate to the user's profile,the 100 most appropriate advertisements, and the 20 most appropriatesporting team reports, etc. By providing the additional content to theUAEC, the AES may randomize the selection of content. Further, theadditional content permits the AESF to skip past AE's if the usersupplies negative feedback, then obtain additional content withouthaving to access the FS 34 or DB 44. Instead, the cache is accessed toretrieve AE's. Accordingly, a PRS using a UAEC 150 generates 2000transactions per hour (one per user login) to the FS 34 and DB 36,rather than 2000 transactions every 15 seconds. The cached systemgenerates 0.5 transactions per second (as opposed to the 133transactions per second that would occur without a cache). Thistransaction load is quite feasible with currently available databasesystems.

Although caching has several benefits, it should be noted that the useof the UAEC 150 is not always appropriate to cache AE's for an entirehour. For example, AE's for stock quotes, weather, and traffic may beupdated more frequently than every hour. Accordingly, these types oftime critical information are retrieved as needed from the DB servers.Even so, because the expected number of stock, weather, or trafficreports per user per hour is relatively low, directly accessing the DB36 and FS 34 for these types of audio elements only requires, onaverage, an additional 0.5 transactions per second.

In addition, it is also possible to handle traffic, weather, and stockreports as special cases in order to permit AE's to be dynamicallyupdated on the FS 34 without any changes made to either the DB 44 or AES38. Specifically, the AE identification for the “current traffic” neverchanges. The AE file corresponding to the AE identification number,however, is updated as the conditions change. As a result, the trafficreport that is played to the user is updated as needed with noadditional transactions against the DB and no changes to the AES.

Another aspect of the present invention involves a highly efficientcomparison method within each AESF 42 for selecting audio elements basedon a user's profile. An exemplary audio element that is selected basedon the user's profile is an advertising AE. In operation, the AESselects an advertisement AE for a particular user based on the set ofdemographic properties stored in the UPDEM component 56 of each userprofile. Typical demographic information may include, for example, anindication that the user has the following demographic information:MALE, UNDER-20, LIKES-COMPUTERS, INTERESTED-IN-PURCHASING-COMPUTER,CAR-OWNER, HOMEOWNER, etc. It should be understood that this list ofdemographics is merely intended to be exemplary. Any number ofdemographic information may be stored in the UPDEM 56 without departingfrom the scope of the present invention. The AESF then matches anappropriate advertisement based on the user's demographic information.The purpose of matching an advertisement to a particular user is thatthe advertiser wishes to pay only for advertisements shown to aparticular sub-group of the PRS audience. Alternatively, the advertisermay wish to pay more for advertisements played to a particular sub-groupof the PRS audience. For example, an advertiser may wish to match thesex of a particular user to a particular advertisement (e.g., a golfshop wants to advertise specifically to men).

In an embodiment, the present invention solves the inefficienciesassociated with using traditional selection methods for choosing anappropriate AE. Specifically, the present invention contemplates the useof a User Property Comparison Mechanism (UPCM), which comprises a set ofdata structures in the UPDB 46 and the AEDB 44, and a software routinein the AES 38 for efficiently comparing these properties. As illustratedin FIG. 16a, the illustrated data structures represent the targetdemographics for a particular audio element; and as illustrated in FIG.16b, the data structures represent the user demographics.

As shown in FIGS. 16a-c, the UPCM utilizes a trinary property (TRIT)representation to store and efficiently compare these demographicproperties. For most demographic properties, the information isinherently trinary (i.e., three-valued, rather than two-valued). Forexample, a particular user may be female and therefore the value of thedemographic property MALE would be “false.” However, if that user weremale, then the demographic property MALE would have the value “true.”Finally, it is possible that for other users in the PRS system that thevalue of MALE is unknown (i.e., because they have not chosen to answerthat question and that information is unavailable from other sources).Accordingly, the valued store for the MALE demographic property for auser may potentially take on three values (MALE, NOT-MALE (female), andUNKNOWN), and is therefore trinary.

Similarly, the demographic properties in an UPDEM 56 of the presentinvention are inherently trinary. For example, an advertiser may wish toprovide advertisements only to males. Accordingly, the demographicproperty MALE would be set to “true” for a particular advertisement.Another advertiser may not care if the user is MALE. Accordingly, theproperty would have to be represented as something other than true orfalse. Thus, based on the foregoing, the advertising AE properties arealso trinary.

The trinary representation is important because for the each currentuser, the AES tests all ads to determine if the user is in thatadvertisement's demographic target audience. Each of theseadvertisements is a candidate for inclusion in the PRS user customizedbroadcast. However, given that there are potentially several hundredproperties, storing each property as a separate column in a databasetable can be very inefficient, perhaps requiring an entire word ofmemory per demographic property per user. One conventional alternativeis to pack several properties into a single word of memory and to thenstore the word as a single column. Then, in order to match theproperties, the matching program must first extract an entire word fromthe column and compare it. These operations are not efficient and aresometimes unavailable within commercial database packages.

Accordingly, the TRIT representation is efficient both in storage andretrieval. As illustrated in FIG. 16a, an exemplary TRIT representationfor each property is stored as 1 bit in two separate words. Given that atypical computer word is either 32 or 64 bits, either 32 or 64properties can be stored in a pair of words. The 32 (or 64) propertiesstored in these two words can be compared in parallel by directoperations on the words. The properties need never be extracted. In thecase of an advertisement, the two computer words may be known as WANT162 and TARGET 164. For each user, the two words may be known as KNOWN166 and VALUE 168. The nth bit of the WANT and TARGET words isassociated with the nth demographic property (for example, the 4th bitmay be associated with the property MALE). The nth bit of the KNOWN andVALUE words are also associated with the nth demographic property.

In an exemplary embodiment, the representation used in these words is asfollows: if the target demographic for an advertisement is for maleusers, both the WANT bit (indicating that the advertisement should betargeted only to listeners who fit into this demographic) and the TARGETbit (indicating that the advertiser wants to target the advertisement tousers who are male) for the MALE property is set (have the value “1”).Alternatively, if the target is female users, then WANT=1 and TARGET=0.Finally, if the target is both men and women, then the particulardemographic is not at issue, and WANT=0 and TARGET is unused and can beeither value.

User demographic information is represented similarly. If a user ismale, the KNOWN bit (indicating that the particular demographic “is”“known”) is set to 1, and the VALUE bit (representing whether theparticular user falls includes the particular demographic) is also setto 1. Similarly, if the user is female, then KNOWN=1 and VALUE=0. If thesex of the user is unknown, then KNOWN=0 and VALUE can be either 1 or 0.Referring only to a single property, a user is in the target audience ofthe advertisement if the following Boolean logic statement is true:

(not WANT) or (KNOWN and (TARGET xnor VALUE))

Accordingly, because this determination can be made using Boolean logic,an important aspect of the present invention is that the TRITrepresentation allows the properties in the WANT, TARGET, KNOWN, andVALUE words to be compared at the same time using bit-wise binaryoperations that are both common and very efficient in computerprocessors (taking one cycle or less). The bit-wise binary operationsresult in a word 169 containing the results of comparing the 32 (or 64)properties. Thus, if each of the bits in the resulting word is 1, thenthe user is in the target audience of the advertisement.

In addition, most modern-day CISC (complex instruction set computer)systems have a native ‘xnor’ (not exclusive-or) operation, on systemsthat do not, the xnor functionality can be replicated by combining otherprimitive Boolean operations:

If ‘xor’ (exclusive-or) is available:

(not WANT) or (KNOWN and (not (TARGET xor VALUE)))

otherwise:

(not WANT) or (KNOWN and ((TARGET and VALUE) or ((not TARGET) and (notVALUE)))

can be used. In all three embodiments, the computation is extremelyefficient because the operations “not,” “and, ” “or,’” “xor,” and“‘xnor’” are both numerically simple, and also fundamental to theoperation of modern computing, and have therefore been highly optimized.In most situations each operation will take only a single CPU cycle.

In an alternate embodiment, if the total number of properties is greaterthan the number of bits in a word of memory, then multiple TRIT wordsmay be used. The user is in the target audience for the advertisement ifall of the TRIT word comparisons match.

In yet another embodiment of the present invention, the TRIT concept canbe easily extended to properties that can take on more than 2 values.For example, one such property might be the CITY demographic (indicatingthe city where the user lives), for which there may be hundreds ofpotential values. This demographic could be stored as a single 9-bitproperty (which would allow for a total of 512 possible cities). Then,as illustrated in FIGS. 17a-c, the TRIT representation may be extendedso that 9 bits of the WANT word 170, the TARGET word 172, the KNOWN word174, and the VALUE word 176 are associated with the CITY demographicproperty. If the advertiser wishes to target a particular city, then all9 of the WANT bits are set 1. The TARGET is set to the city code (in theillustrated embodiment, the city code for Austin is set as “100100110”).If the user enters the user's city of residence into the PRS system,then all 9 of the KNOWN bits are set to 1 and the VALUE bits are set tothe code corresponding to that city. And once again, performing the sameBoolean algebra, when all the bits in the result 178 are “1's,” then theuser has indicated that they live in the city to which the advertisementis targeted.

In yet another aspect of the present invention, the PRS may include anexclusion list (XLIST) scheme for insuring a variety of content to auser. According to this aspect of the invention, the XLIST is used bythe AES to insure that two identical, similar, or closely related AE'sare not played in close sequence. The XLIST scheme comprises a datastructure 180 (as illustrated in FIG. 18) in the DB 36 that includesinformation about the most recently played AE's, and a softwarecomponent of the AES that updates and maintains the XLIST data structure180. Once created, the XLIST is used by the AES in the selection of thenext AE of a similar type content (e.g., song, news, etc.).

In an embodiment, one exclusion list (XLIST) is created for each type ofAE played by the PRS. In an exemplary embodiment, the XLIST isrepresented as a ring buffer in which the AEIDs are maintained for the Nmost recently played AE's (where N is selected by the system designer).As is well known in the computer science field, a ring buffer is a fixedlength buffer in which the newest element to be added to the buffer isadded by writing over the oldest element. After an audio element isplayed by the PRS, the AES stores the AEID in the XLIST data structurecorresponding to that type of AE. Thus, the XLIST may be used by the AESto insure that two identical, similar, or closely related AE's are notplayed in close sequence.

One example of the utility of the XLIST is in the selection of songs. Inoperation, the AES selects and caches a number of songs based on theinformation contained in the UPMP (music preference) portion of the userprofile. In an embodiment, the 100 top songs that meet the user'scriteria are retrieved and stored. If the user's preferences have notchanged since the last log in, the same 100 songs may be retrieved andcached on the next login. And if the AES selects the songs in order ofranking, the same songs may be played every time the user logs in. Evenif the selection of an AE is random, there is a real risk that the samesongs may be chosen each time a user logs into the system. In the caseof a song, the information stored includes the song id 182 and the songartist 184. Using this information the AES can reject songs that areeither identical to a recently played song or have the same artist.

The XLIST may also be created for other types of AE's like news reportsor traffic reports. In the case of a traffic report, the AE's associatedwith the set of roads driven by the user are returned to the AES. Whenconstructing a traffic report, it is important that a particular AE thatrefers to a particular road, should not be played twice.

In some cases, the user may wish to hear multiple songs by the sameartist. In conventional radio, this practice is called playing a“two-fer.” Accordingly, the XLIST may also be used to insure that pairsof songs from the same artist are played.

FIG. 19 provides a block diagram of an exemplary flow diagram of asystem for using the XLIST of the present invention. Once an audioelement is selected, the AEID is compared to the AEID's in the XLISTcorresponding to the type of AE selected (190 a-n). If any of thecomparisons results in a determination that the selected audio elementis in the XLIST (represented by the “OR” decision box at 192), then theaudio element is excluded at 194. If the comparison does not establishthat the selected audio element is in the XLIST, then the audio elementis accepted at step 196.

While the invention may be adaptable to various modifications andalternative forms, specific embodiments have been shown by way ofexample and described herein. However, it should be understood that theinvention is not intended to be limited to the particular disclosedembodiments. Rather, the invention is to cover all modifications,equivalents, and alternatives falling within the spirit and scope of theinvention as defined by the claims. Moreover, the different aspects ofthe disclosed system and methods may be utilized in various combinationsand/or independently. For example, the present invention is illustratedas providing a customized radio broadcast to one or more users. However,it should be understood that the concepts and inventions disclosedherein may be used in the transmission of other types of customizeddata. Specifically, the concepts and inventions disclosed herein may beused to provide customized video content to one or more users based onuser profiles.

What is claimed is:
 1. A method of generating a number audio element forplaying a desired number in an audio system, comprising: a) storing aplurality of audio elements used to represent a subset of the range ofnumbers; b) defining a plurality of match types used to determine if oneor more matching audio element exists in the subset of the range ofnumbers; c) defining a plurality of accuracy prefixes representative ofthe error associated with any rounding of the desired number to beplayed; d) setting the accuracy prefix to a value representing an exactmatch between the desired number and a number audio element in thestored subset of audio elements representative of the range of numbers;e) filtering the audio elements to determine if an exact match exists;f) if an exact match does not exist, rounding the desired number to apre-determined level of precision to create an estimated desired number;g) setting the accuracy prefix to a value representing the errorassociated with any rounding of the desired number to be played; h)filtering the audio elements to determine if an exact match existsbetween the estimated desired number and any of the plurality of audioelements used to represent a subset of the range of numbers; and i)repeating steps f)-g) until such time as an exact match has beendetermined between the estimated desired number and any of the pluralityof audio elements used to represent a subset of the range of numbers. 2.The method of generating a number audio element of claim 1 furthercomprising inserting an audio element prefix corresponding to theaccuracy prefix.
 3. The method of generating a number audio element ofclaim 1 further comprising transmitting the number audio element to aremote user.
 4. The method of generating a number audio element of claim1 further comprising filtering the audio elements to eliminate audioelements that are not announced by a pre-determined DJ.
 5. The method ofgenerating a number audio element of claim 1 wherein the number audioelement is a time audio element.
 6. The method of generating a timeaudio element of claim 5 wherein the match types include a hour-minutematch type.
 7. The method of generating a time audio element of claim 5wherein the match types include a minute-hour match type.
 8. The methodof generating a time audio element of claim 5 wherein the match typesinclude a minute-hour+1 match type.
 9. The method of generating a timeaudio element of claim 5 wherein the accuracy prefix indicates that thedesired number to be played is before the estimated desired number. 10.The method of generating a time audio element of claim 5 wherein theaccuracy prefix indicates that the desired number to be played is afterthe estimated desired number.
 11. The method of generating a time audioelement of claim 5 wherein the predetermined level of precision is 5minutes.
 12. The method of generating a time audio element of claim 5wherein the predetermined level of precision is 10 minutes.
 13. Themethod of generating a number audio element of claim 1 wherein thenumber audio element is a stock quote audio element.
 14. The method ofgenerating a stock quote audio element of claim 13 wherein the matchtypes include a dollar-fraction match type.
 15. The method of generatinga stock quote audio element of claim 13 wherein the match types includea hundreds-ten-one-fraction match type.
 16. The method of generating astock quote audio element of claim 13 wherein the accuracy prefixindicates that the desired number to be played is over the estimateddesired number.
 17. The method of generating a stock quote audio elementof claim 13 wherein the accuracy prefix indicates that the desirednumber to be played is under the estimated desired number.
 18. Themethod of generating a stock quote audio element of claim 13 wherein thepredetermined level of precision is in dollars.
 19. The method ofgenerating a number audio element for playing a desired number in anaudio system of claim 1, wherein the audio system is a radio broadcastsystem.
 20. The method of generating a number audio element for playinga desired number in an audio system of claim 1, wherein the audio systemis a telephone system.
 21. The method of generating a number audioelement for playing a desired number in an audio system of claim 1,wherein the audio system is included in an automated teller machine. 22.A processor-based broadcast system for generating a number audio elementrepresentative of a desired number to be broadcast within a range ofnumbers, comprising: a) means for storing a plurality of audio elementsused to represent a subset of the range of numbers; b) means fordefining a plurality of match types used to determine if one or morematching audio element exists in the subset of the range of numbers; c)means for defining a plurality of accuracy prefixes representative ofthe error associated with any rounding of the desired number to bebroadcast; d) means for setting the accuracy prefix to a valuerepresenting an exact match between the desired number and a numberaudio element in the stored subset of audio elements representative ofthe range of numbers; e) means for filtering the audio elements todetermine if an exact match exists; f) means for rounding the desirednumber to a pre-determined level of precision to create an estimateddesired number if an exact match does not exist; g) means for settingthe accuracy prefix to a value representing the error associated withany rounding of the desired number to be broadcast; h) means forfiltering the audio elements to determine if an exact match existsbetween the estimated desired number and any of the plurality of audioelements used to represent a subset of the range of numbers; and i)means for repeating steps f)-g) until such time as an exact match hasbeen determined between the estimated desired number and any of theplurality of audio elements used to represent a subset of the range ofnumbers.